Today's increased attention to nature and the environment has resulted in unprecedented efforts to encourage grasses, low-growing ground cover, and wildflowers on rights-of-way. Thus, individual plant control treatments are desirable to remove tall-growing woody plants low-profile vegetation control programs. Not only do such treatment programs result in effective, long lasting brush control, they leave non-target plants virtually untouched. This allows annual and perennial grasses and other desired plants to thrive because they are freed from competition for moisture, nutrients and sunlight.
One such treatment program consists of the use of basal bark or stem application of a herbicide to control undesired vegetation. As previously stated, control of such undesired vegetation is typically desirable along roadway, drainage and utility right-of-ways. This particular method is attractive because it provides not only vegetation control, but also efficient placement and utilization of the herbicidal composition on an individual basal bark or stem placement. Unlike nonselective herbicidal products or methods which can damage desirable grasses or plants, the present invention promotes the development of desired ground cover resulting in aesthetically pleasing rights-of-way.
Basal bark or stem applications of herbicidal compositions requires the herbicide to pass through the bark into the appoplast or symplast of the plant where movement to the site of activity can take place. It is well known that when applying the herbicide by basal or stem application, it is desirable to dissolve the herbicide in a non-aqueous organic carrier. As currently used, such carriers consist of petroleum distillates, such as fuel oils, for example, diesel oil or kerosene. These petroleum distillate carriers provide for penetration of the herbicide through the bark of the vegetation to be controlled.
However, these carriers present risks not only to the surrounding environment, but also to the applicator as well. When making basal or stem applications, application technique and packaging may not eliminate all contact of the herbicidal composition with skin or clothing. Also, due to applicator technique or wind conditions, over-spray onto surrounding areas may result during the application. Herbicide carriers such as diesel fuel and kerosene, are low grade petroleum products containing impurities, such as benzene, benzene(a)pyrene, and polycyclic aromatic hydrocarbons, and may pose a potential risk to human health. Thus, in order to pose less environmental and applicator exposures to petroleum distillates, new alternative herbicidal carriers are desirable in efforts to control undesired vegetation. In addition, new carriers which may increase uptake, translocation, or efficacy of the active herbicide are also desirable.